1. Field of the Invention
The present invention relates generally to self-propelled agricultural bale wagons and, more particularly to bale wagons of the type adapted to pick up crop material bales in the field and automatically form stacks of these bales utilizing a variety of stacking patterns to form a stable, interlocked stack of bales.
2. Description of the Related Art
A bale wagon by G. E. Grey is described in U.S. Pat. No. 2,848,127, and is principally adapted for stacking bales and is basically comprised of three tandomly arranged cooperating tables. In operation, the basic Grey wagon functions to pick up bales, form them into a composite stack, and subsequently discharge the entire stack in a storage area.
Present day practices in crop harvesting involve the formation of bales of crop material such as hay or other crops into stacks for storage by using an automatic bale wagon. One type of bale wagon that has achieved wide spread commercial acceptance is the automatic bale wagon which uses three tables as illustrated and described in U.S. Pat. No. 4,203,695 issued to Edward J. Wynn et al.
Such bale wagons include a first table which receives bales from a bale loader or pick up device mounted on the bale wagon. The first table accumulates a predetermined number of bales with the bales being arranged in a row in a pattern determined by a computer on board the bale wagon. A second table receives the rows of bales from the first table and accumulates several such rows. This group of rows is commonly referred to as a “tier”. A third table or load bed then receives the tiers from the second table and accumulates these tiers to form a “stack” on the load bed.
Once the stack has been accumulated on the load bed, it may be unloaded by pivoting the load bed 90 degrees and depositing the stack on the ground or other surface so that the first tier of bales which was accumulated on the second table is now the lowermost tier of the stack on the ground surface. In order to enhance the stability of the stack, it is desirable to vary the arrangement of the tiers within the stack, and the on-board computer is used to control tier pattern selection and formation on the wagon and the formation of bales into a predetermined sequence of tier patterns to form a block for stacking.
It would be very beneficial to have a pattern selection process that does not add another complex control, but reduces the time, effort, and frustration required to choose a desired pattern.
Current bale collecting system on self-propelled bale wagons require that the operator input the bale size being collected into the controller in order for the control system to determine the stack pattern to be used. This is fine provided the operator does not inadvertently select the incorrect bale size. If he does select the incorrect size, for example, selecting three foot bales when he is actually collecting four foot bales, the prior art systems cannot sense that the incorrect stack pattern is being used and will load three four foot bales when only two should be loaded. This can result in damage to the clamp mechanism when the third bale strikes the second bale on the second table, or a bale can become caught between the front of the second table and the clamp mechanism or cab. While neither of these scenarios present a danger to the operator, the time required to remove a very large and heavy bale from the bale wagon takes additional time and probably requires that the bale be cut, which is a total loss. Further, current systems cannot detect when a bale has broken during the clamping or lifting motions. In these cases, the operator must manually intervene to reset the system to inform the controller that a bale was not deposited on the second table. Likewise, if a 3×4 bale is sitting in its side in the field, current control systems will deposit the bale on its side on the second table, which will result in an uneven, unstable stack.
What is needed in the art is a bale wagon system that eliminates the mistakes of the prior art stacking systems and stacks bales in an efficient cost saving manner.